A275186 Number of 6 X n 0..2 arrays with no element equal to any value at offset (-2,-1) (-1,0) or (-1,1) and new values introduced in order 0..2.

16, 37, 181, 914, 4603, 23313, 117916, 596625, 3018913, 15274618, 77286999, 391054261, 1978648444, 10011529573, 50656125413, 256308871218, 1296866472387, 6561859014441, 33201563019036, 167992603723721, 850005614599481

Offset: 1

Author

R. H. Hardin, Jul 19 2016

Keywords

• nonn

Examples

			Some solutions for n=4:
..0..0..1..2. .0..0..1..2. .0..0..1..1. .0..0..1..2. .0..1..2..0
..2..2..0..1. .2..2..0..1. .1..2..0..0. .1..2..0..1. .2..0..1..2
..1..1..2..2. .1..1..2..2. .0..1..2..2. .0..1..2..2. .1..2..0..1
..2..0..0..1. .0..0..1..1. .2..0..0..1. .2..0..1..1. .0..1..2..0
..1..2..2..0. .2..2..0..0. .1..2..2..0. .1..2..2..0. .2..0..1..2
..0..1..1..2. .1..1..1..2. .0..1..1..1. .0..0..1..2. .1..2..0..1
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Crossrefs

Row 6 of A275183.

Formula

Empirical: a(n) = 2*a(n-1) + 12*a(n-2) + 19*a(n-3) - 4*a(n-4) - 12*a(n-5) - 16*a(n-6) for n>7.

Empirical g.f.: x*(16 + 5*x - 85*x^2 - 196*x^3 - 36*x^4 + 40*x^5 + 112*x^6) / ((1 - x)*(1 - x - 13*x^2 - 32*x^3 - 28*x^4 - 16*x^5)). - Colin Barker, Feb 01 2019